For those of you who have added plywood to the top of your aluminum bench seats, how thick of plywood? 1/2, 5/8, or 3/4? I am leaning towards 5/8 (splitting the difference) because I am also adding seat bases that will connect to the plywood via tee nuts installed on the underside of the plywood. The plywood will be attached to the aluminum bench with bolts and plus nuts.

but why add plywood in the first place? The stuff is heavy, it rots over time, and it is not necessary in order to secure your seats. If you just must add something try this on page 40ish: http://www.akmccallumco.com/pdf/ma.pdf

If you go the plywood route, take a look at MDO. It's the stuff highway signs are made of and very durable. I've got some still in my '82 boat that is it great shape.

I don't think you need more than 1/2" - and for 1-2 seats it wouldn't add that much weight. The bench seats in my Bayrunner are 1/2" MDO plywood attached to vertical aluminum panels with flanges (no aluminum "bench" under the seating area). I wouldn't hesitate to bolt a seat on (in fact, after looking at those Lowes brackets/accessories, I'm taking another look at it.

The boat is an Alumacraft 1236 where the aluminum benches go to the floor. I wanted to add some plywood to the bench tops so that there would be something more substantial to add a folding seat. The other wrinkle is that the bench seats in the alumacraft have a large rounded bullnose profile. The other reason for the plywood is that if I was unhappy with a seat base or seat position it is pretty easy to remove a piece of plywood, and bolt a new piece of plywood to the existing holes in the aluminum bench and attach the new seat or seat base, without ending up with an aluminum bench that looks like swiss cheese. I recently added a seat to another boat (that has access under the wooden bench) and ended up having to move the seat due to balance issues. The plywood would allow for fine tuning with only having to replace plywood if necessary.

So, the plan is to use plus nuts/rivnuts/nutserts to attach a piece of plywood to the top of the aluminum bench seat. The seat base will then be attached only to the plywood.

Who is online

You cannot post new topics in this forumYou cannot reply to topics in this forumYou cannot edit your posts in this forumYou cannot delete your posts in this forumYou cannot post attachments in this forum

Jump to:

Join the free forum or login with your account and the annoying banner goes away